Xenurobrpconinae Mpers and Böhlke, 1956

Melo, Bruno F, Ota, Rafaela P, Benine, Ricardo C, Carvalho, Fernando R, Lima, Flavio C T, Mattox, George M T, Souza, Camila S, Faria, Tiago C, Reia, Lais, Roxo, Fabio F, Valdez-Moreno, Martha, Near, Thomas J & Oliveira, Claudio, 2024, Phylogenomics of Characidae, a hyper-diverse Neotropical freshwater fish lineage, with a phylogenetic classification including four families (Teleostei: Characiformes), Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (1), pp. 1-37 : 8-9

Xenurobrpconinae Mpers and Böhlke, 1956

Type genus: Xenurobrycon Myers and Miranda Ribeiro, 1945.

Included genera: Tytocharax Fowler, 1913 and Xenurobrycon . Not sampled: Iotabrycon , Ptychocharax Weitzman et al., 1994 , and Scopaeocharax Weitzman and Fink, 1985 .

Definition: The least inclusive crown clade that contains Xenurobrycon macropus Myers and Miranda Ribeiro, 1945,

Iotabrycon praecox Roberts, 1973 , Ptychocharax rhyacophila Weitzman et al., 1994, Scopaeocharax rhinodus (Böhlke 1958) , and Tytocharax madeirae Fowler, 1913 . This is a minimum-crown-clade definition. See Figure 3 for a reference phylogeny of Xenurobryconinae. Although Iotabrycon praecox , Ptychocharax rhyacophila , and Scopaeocharax rhinodus are not included in the reference phylogeny, they resolve as a monophyletic group with Tytocharax tambopatensis and Xenurobrycon macropus in a phylogenetic analysis of a dataset of mtDNA, nuclear genes, and morphology (Ferreira et al. 2011:fig. 1).

Etymology: From the ancient Greek ξένος (zˈiːno͡ʊz) meaning strange or unusual, οὐΡα (ˈuːɹˈɑː) meaning tail, and ΒΡύκω (bɹˈʊka͡ʊ) meaning to bite.

Remarks: Myers and Böhlke (1956) erected the tribe Xenurobryconini to include Xenurobrycon and Tytocharax based on the similarity of their caudal fin morphology. The tribe Xenurobryconini was expanded to include Argopleura Eigenmann, 1913 , Iotabrycon , and Scopaeocharax (Weitzman and Fink 1985) , and later Chrysobrycon Weitzman and Menezes, 1998 and Ptychocharax (Weitzman and Menezes 1998) . Thomaz et al. (2015) considered Argopleura as incertae sedis and transferred Chrysobrycon to their Stevardiini . Mirande (2019) corroborated the monophyly of Xenurobryconini (sensu Thomaz et al. 2015), and tentatively included Cyanogaster Mattox et al., 2013 , in this clade supported by four synapomorphies. Our phylogenetic analysis of the UCE loci indicates that Cyanogaster is placed closer to species of Aphyocharacinae . Ferreira et al. (2021) included Iotabrycon , Ptychocharax , Scopaeocharax, Tytocharax , and Xenurobrycon in Xenurobryconini based on four morphological synapomorphies. In other phylogenomic analyses, Scopaeocharax was resolved as the sister-lineage of Cyanocharax Malabarba and Weitzman, 2003 or Diapoma Cope, 1894 ( Arcila et al. 2017, Betancur-R. et al. 2019). Although UCE data for Iotabrycon , Ptychocharax , and Scopaeocharax are not yet available, they are included in Xenurobryconinae along with Tytocharax and Xenurobrycon based on phylogenetic analyses of a combined mtDNA, nuclear genes, and morphology dataset (Ferreira et al. 2021).